An example of a braking corrector provided with a protective cap is given in French Pat. No. 1,483,088. The document describes a cylindrical corrector having, at one end, a base surface on which a cap is mounted. An annular mounting component is joined to the cap and the assembly is retained by a circlip which is engaged in a groove in the cylindrical wall of the corrector body. This device has the disadvantage that the base surface and the groove must be machined in the body and makes the mounting and removal of the cap a delicate operation.